Development of a low-level 39Ar calibration standard – Analysis by absolute gas counting measurements augmented with simulation. (August 2017)

• Record Type: Journal Article
• Authors: Williams, R.M.; Aalseth, C.E.; Brandenberger, J.M.; Day, A.R.; Finn, E.; Fuller, E.S.; Hoppe, E.W.; Humble, P.H.; Keillor, M.E.; Mace, E.K.; Myers, A.W.; Overman, C.T.; Panisko, M.E.; Seifert, A.; White, S.K.
• Is Part Of: Applied radiation and isotopes. Volume 126(2017:Aug.)
• Page Start: 243
• Page End: 248
• Publication Date: 2017-08
• Subjects: Absolute radiation measurement -- Length compensated proportional counting -- Ultra-low background -- Electroformed copper -- Uncertainty Analysis; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2017.02.018
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: This paper describes the generation of 39 Ar, via reactor irradiation of potassium carbonate, followed by quantitative analysis (length-compensated proportional counting) to yield two calibration standards that are respectively 50 and 3 times atmospheric background levels. Measurements were performed in Pacific Northwest National Laboratory's shallow underground counting laboratory studying the effect of gas density on beta-transport; these results are compared with simulation. The total expanded uncertainty of the specific activity for the ~50× 39 Ar in P10 standard is 3.6% (k=2). Highlights: 39 Ar is generated via reactor irradiation of potassium carbonate. Low-level standards are produced to assist in ground water age-dating studies. Quantification using length compensated proportional counting is performed. Wall- and threshold-effects are studied and discussed in terms of uncertainty.